The invention relates to a size sensing X-ray cassette tray for X-ray equipment adated for automatically controlling a conventional collimator for adjusting the size of a X-ray beam in response to the size of the cassette upon the cassette tray. Prior art example devices for adjusting the size of an X-ray beam are disclosed in one or more of the following United States and British patents:
2,912,202, Petrick 3,206,604, Burehell PA1 4,048,700, Koerner et al 3,502,878, Steward et al PA1 3,091,696, Peyser 3,518,434, Lombardu PA1 3,099,747, Thomas et al 3,518,435, Kok PA1 3,130,313, Tilling 3,581,094, Peyser et al PA1 3,150,263, Callin 3,764,808, Lackey et al PA1 British Patent 1,170,303 (1969).